Various electronic devices have been used in every aspect of modern day living with the enhancement of technology: especially the development of portable electronic devices has greatly advanced over the years.
The more a user fascinates about and uses a portable electronic device, the power consumption of the portable electronic device increases. If the user of the portable electronic device has some important or emergency documents to be done thereon and the portable electronic device is running out of power without a spare battery or other power supply devices and there is no charging socket or other charging platforms nearby, it may suspend any personal work progress and may also delay progress of any team work, possibly causing damage to a company's business, leading to uncountable losses. Therefore, power management is quite important for a portable electronic device.
In addition, it would be better if a modern portable electronic device is as small as possible. Herein, if a power management function can be fulfilled on a present circuit structure in the portable electronic device without adding extra circuits or electronic components, the burden on designing the portable electronic device to accomplish such a function may be reduced and manufacturing costs may be saved. This is advantageous to the manufacturers, suppliers and the users.